Christos A. Papadimitriou

Assessment of somatic k-RAS mutations as a mechanism associated with resistance to EGFR-targeted agents: a systematic review and meta-analysis of studies in advanced non-small-cell lung cancer and metastatic colorectal cancer

BACKGROUND Somatic mutations of the k-RAS oncogene have been assessed as a mechanism of de-novo resistance to epidermal growth factor receptor (EGFR) tyrosine-kinase inhibition in patients with non-small-cell lung cancer (NSCLC), and to anti-EGFR monoclonal antibodies in patients with metastatic colorectal cancer (mCRC). The aim of this systematic review and meta-analysis was to assess if k-RAS mutations represent a candidate predictive biomarker for anti-EGFR-targeted therapeutic strategies in mCRC and NSCLC. METHODS We systematically identified articles pertaining to k-RAS mutational status in patients with NSCLC treated with tyrosine-kinase inhibitors (TKI), and patients with mCRC treated with any anti-EGFR-based regimens. Eligible studies had to report complete responses (CR) and partial responses (PR), stratified by k-RAS mutational status. Potential between-study heterogeneity was accommodated by use of random-effects models for bivariable meta-analysis of sensitivity and specificity (the primary endpoints). The positive and negative likelihood ratios (+LR and -LR, respectively) of k-RAS mutations for predicting an absence of response were considered as secondary endpoints and were calculated by use of pooled estimates for sensitivity and specificity. FINDINGS Of 252 retrieved manuscripts, 17 were deemed eligible for the NSCLC meta-analysis (165 of 1008 patients with mutated k-RAS). The presence of k-RAS mutations was significantly associated with an absence of response to TKIs (sensitivity=0.21 [95% CI 0.16-0.28], specificity=0.94 [0.89-0.97]; +LR=3.52; -LR=0.84). Of 68 retrieved manuscripts reporting on anti-EGFR monoclonal-antibody-based treatment of mCRC, eight studies were deemed eligible for the final analysis (306 of 817 patients with mutated k-RAS). The presence of k-RAS mutations was significantly associated with an absence of response to anti-EGFR monoclonal-antibody-based treatments (sensitivity=0.47 [0.43-0.52]; specificity=0.93 [0.83-0.97]; +LR=6.82; -LR=0.57). INTERPRETATION This analysis provides empirical evidence that k-RAS mutations are highly specific negative predictors of response (de-novo resistance) to single-agent EGFR TKIs in advanced NSCLC; and similarly to anti-EGFR monoclonal antibodies alone or in combination with chemotherapy in patients with mCRC. The low sensitivity and relatively high -LR of k-RAS mutations for determining non-responsiveness clearly shows that additional mechanisms of resistance to EGFR inhibitors exist.

Docetaxel and Cisplatin With Granulocyte Colony-Stimulating Factor (G-CSF) Versus MVAC With G-CSF in Advanced Urothelial Carcinoma: A Multicenter, Randomized, Phase III Study From the Hellenic Cooperative Oncology Group

PURPOSE The combination of methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) represents the standard regimen for inoperable or metastatic urothelial cancer, but its toxicity is significant. We previously reported a 52% response rate (RR) using a docetaxel and cisplatin (DC) combination. The toxicity of this regimen compared favorably with that reported for MVAC. We thus designed a randomized phase III trial to compare DC with MVAC. PATIENTS AND METHODS Patients with inoperable or metastatic urothelial carcinoma; adequate bone marrow, renal, liver, and cardiac function; and Eastern Cooperative Oncology Group performance status < or = 2 were randomly assigned to receive MVAC at standard doses or docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2) every 3 weeks. All patients received prophylactic granulocyte colony-stimulating factor (G-CSF) support. RESULT Two hundred twenty patients were randomly assigned (MVAC, 109 patients; DC, 111 patients). Treatment with MVAC resulted in superior RR (54.2% v 37.4%; P =.017), median time to progression (TTP; 9.4 v 6.1 months; P =.003) and median survival (14.2 v 9.3 months; P =.026). After adjusting for prognostic factors, difference in TTP remained significant (hazard ratio [HR], 1.61; P =.005), whereas survival difference was nonsignificant at the 5% level (HR, 1.31; P =.089). MVAC caused more frequent grade 3 or 4 neutropenia (35.4% v 19.2%; P =.006), thrombocytopenia (5.7% v 0.9%; P =.046), and neutropenic sepsis (11.6% v 3.8%; P =.001). Toxicity of MVAC was considerably lower than that previously reported for MVAC administered without G-CSF. CONCLUSION MVAC is more effective than DC in advanced urothelial cancer. G-CSF-supported MVAC is well tolerated and could be used instead of classic MVAC as first-line treatment in advanced urothelial carcinoma.

Taxane resistance in breast cancer: Mechanisms, predictive biomarkers and circumvention strategies

BACKGROUND Taxanes are established in the treatment of metastatic breast cancer (MBC) and early breast cancer (EBC) as potent chemotherapy agents. However, their therapeutic usefulness is limited by de-novo refractoriness or acquired resistance, which are common drawbacks to most anti-cancer cytotoxics. Considering that the taxanes will remain principle chemotherapeutic agents for the treatment of breast cancer, we reviewed known mechanisms of resistance in with an outlook of optimizing their clinical use. METHODS We searched the PubMed and MEDLINE databases for articles (from inception through to 9th January 2012; last search 10/01/2012) and journals known to publish information relevant to taxane chemotherapy. We imposed no language restrictions. Search terms included: cancer, breast cancer, response, resistance, taxane, paclitaxel, docetaxel, taxol. Due to the possibility of alternative mechanisms of resistance all combination chemotherapy treated data sets were removed from our overview. RESULTS Over-expression of the MDR-1 gene product Pgp was extensively studied in vitro in association with taxane resistance, but data are conflicting. Similarly, the target components microtubules, which are thought to mediate refractoriness through alterations of the expression pattern of tubulins or microtubule associated proteins and the expression of alternative tubulin isoforms, failed to confirm such associations. Little consensus has been generated for reported associations between taxane-sensitivity and mutated p53, or taxane-resistance and overexpression of Bcl-2, Bcl-xL or NFkB. In contrary sufficient in vitro data support an association of spindle assembly checkpoint (SAC) defects with resistance. Clinical data have been limited and inconsistent, which relate to the variety of methods used, lack of standardization of cut-offs for quantitation, differences in clinical endpoints measured and in methods of tissue collection preparation and storage, and study/patient heterogeneity. The most prominent finding is that pharmaceutical down-regulation of HER-2 appears to reverse the taxane resistance. CONCLUSIONS Currently no valid practical biomarkers exist that can predict resistance to the taxanes in breast cancer supporting the principle of individualized cancer therapy. The incorporation of several biomarker analyses into prospectively designed studies in this setting are needed.

Hormonal therapy with letrozole for relapsed epithelial ovarian cancer: Long-term results of a phase II study

Objective: We conducted a phase II trial to evaluate the activity of oral letrozole in women with relapsed or recurrent epithelial ovarian cancer. Methods: Twenty-seven patients were treated with letrozole at a dose of 2.5 mg once a day. Patients with measurable or evaluable disease (n = 21) and those with only increasing CA 125 serum levels (n = 6) were eligible. Paraffin-fixed histological sections from tumor specimens resected at the initial laparotomy were assessed for the presence of estrogen, and progesterone receptors. Results: Among the 21 patients with measurable or evaluable disease who were evaluated for response by WHO criteria, we observed one complete and two partial responses for an objective response rate of 15%. Using criteria for CA 125 response we obtained a marker response in 4 of 27 patients (15%), and the marker remained stable in 5 additional patients (18%). Letrozole treatment was generally well tolerated. No correlation was observed between tumor marker response or stabilization and either estrogen or progesterone receptor expression. Conclusion: The results of our study suggest that the aromatase inhibitor letrozole is an agent with some activity and limited toxicity for relapsed ovarian cancer. As we could not find any association between response and hormonal receptor expression, the underlying mechanisms of letrozole action have to be elucidated.

Phase II Trial of Paclitaxel and Cisplatin in Metastatic and Recurrent Carcinoma of the Uterine Cervix

PURPOSE Both paclitaxel and cisplatin have moderate activity in patients with metastatic or recurrent cancer of the cervix, and the combination of these two agents has shown activity and possible synergism in a variety of solid tumors. We administered this combination to patients with metastatic or recurrent cervical cancer to evaluate its activity. PATIENTS AND METHODS Thirty-four consecutive patients were treated on an outpatient basis with paclitaxel 175 mg/m2 administered intravenously over a 3-hour period followed by cisplatin 75 mg/m2 administered intravenously with granulocyte colony-stimulating factor support. The chemotherapy was administered every 3 weeks for a maximum of six courses. RESULTS Sixteen patients (47%; 95% confidence interval, 30% to 65%) achieved an objective response, including five complete responses and 11 partial responses. Responses occurred in 28% of patients with disease within the radiation field only and in 57% of patients with disease involving other sites. The median duration of response was 5.5 months, and the median times to progression and survival for all patients were 5 and 9 months, respectively. Grade 3 or 4 toxicities included anemia in 18% of patients and granulocytopenia in 15% of patients. Fifty-three percent of patients developed some degree of neurotoxicity; 21% of cases were grade 2 or worse. CONCLUSION The combination of paclitaxel with cisplatin seems relatively well tolerated and moderately active in patients with metastatic or recurrent cervical cancer. The significant incidence of neurotoxicity is of concern, and alternative methods of administration of the two agents could be evaluated. Then, further study of this combination, alone or with the addition of other active agents, is warranted.

First-line treatment of advanced non-small-cell lung cancer with docetaxel and cisplatin: A multicenter phase II study

PURPOSE To evaluate the efficacy and safety of the docetaxel-cisplatin combination in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Chemotherapy-naïve patients with histologically confirmed, measurable stage IIIB or IV NSCLC, a World Health Organization (WHO) performance status of 0-2 and adequate bone marrow, renal, hepatic and cardiac function were eligible for the study. Patients received docetaxel (100 mg/m2) as an one-hour infusion on day 1 and cisplatin (80 mg/m2) as a 30-min infusion with appropriate hydration on day 2. Granulocyte colony-stimulating factor (G-CSF; 150 micrograms/m2, SC) was given on days 3 to 13. Treatment was repeated every three weeks. RESULTS Fifty-three patients were enrolled (28 with stage IIIB and 25 with stage IV). One complete and 23 partial responses were observed (overall response rate (OR): 45%; 95% CI: 34.1%-61.8%). The response rate was 57% and 32% in patients with stages IIIB and IV disease (P = NS). The median time to progression was 36 weeks and the median survival 48 weeks; the one-year survival was 48%. Grade 3-4 neutropenia occurred in 23 patients, 15 of whom were hospitalized for neutropenic fever; two patients died of sepsis. Grade 2 neurotoxicity was observed in six patients and grade 3 in five patients; grade 3 fatigue occurred in seven patients, grade 3-4 mucositis in four patients and grade 3-4 diarrhea in six patients. Mild allergic reactions and oedema were observed in five and four patients, respectively. The median dose intensity was 30 mg/m2/week for docetaxel and 24 mg/m2/week for cisplatin, corresponding to 91% and 89% of the specified protocol doses, respectively. CONCLUSIONS The docetaxel-cisplatin combination is an active regimen in advanced NSCLC, but hematologic toxicity remains high despite the prophylactic use of G-CSF.

Docetaxel and cisplatin combination chemotherapy in advanced carcinoma of the urothelium: A multicenter phase II study of the Hellenic Cooperative Oncology Group

PURPOSE Both docetaxel and cisplatin have moderate activity in patients with advanced urothelial cancer. We performed a multicenter phase II study in order to assess the efficacy and toxicity of the combination of these two agents in patients with advanced carcinoma of the urothelium. PATIENTS AND METHODS Sixty-six patients not amenable to curative surgery or irradiation were enrolled onto this cooperative group study and treated on an outpatient basis with docetaxel 75 mg/m2 followed by cisplatin 75 mg/m2, both administered intravenously. Granulocyte-colony stimulating factor was administered subcutaneously at a dose of 5 micrograms/kg daily from day 5 until resolution of neutropenia. The chemotherapy was administered every three weeks for a maximum of six courses in patients without evidence of progressive disease. RESULTS Thirty-four of sixty-six patients (52%, 95% confidence interval 40%-64%) demonstrated objective responses, with eight achieving clinical complete responses and twenty-six partial responses. A multivariate logistic regression analysis indicated that the patients most likely to respond were those without lung metastasis and without weight loss before treatment. The median duration of response was 6.1 months and the median times to progression and survival for all patients were 5 and 8 months, respectively. Absence of anemia, of liver metastases and of weight loss correlated with longer survival. Grade > or = 3 toxicities included granulocytopenia in 33% of patients, anemia in 14%, diarrhea in 13% and emesis in 7% of patients. CONCLUSION The combination of docetaxel and cisplatin appeared relatively well tolerated and moderately active in patients with advanced urothelial cancer. The patients most likely to benefit were those without weight loss and without lung or liver metastases.

Salvage treatment with paclitaxel and gemcitabine for patients with non-small-cell lung cancer after cisplatin- or docetaxel-based chemotherapy: A multicenter phase II study

BACKGROUND To evaluate the tolerance and efficacy of the combination of paclitaxel and gemcitabine as salvage treatment in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Forty-nine patients with measurable NSCLC (PS 0-1: 80%; stage IV: 84%) who progressed or failed first-line chemotherapy were enrolled. Prior chemotherapy was cisplatin-based with (n = 20) or without (n = 22) docetaxel and docetaxel-vinorelbine (n = 7). Patients received gemcitabine (900 mg/m2 i.v.; days 1 and 8) and paclitaxel (175 mg/m2; day 8) every three weeks: G-CSF (150 micrograms/m2/day s.c.; days 9-15) was given prophylactically to all patients. RESULTS One (2%) complete and eight (16%) partial responses were achieved (overall response 18%; 95% CI: 4%-24%); 14 patients (29%) had stable disease and 26 (53%) progressive disease. Six responses were observed in 17 patients who responded to first-line chemotherapy. The median duration of response was seven months, the median TTP eight months and the median survival 11 months. The one-year survival rate was 37%. Grade 3-4 neutropenia occured in six (12%) patients, grade 2-3 neurotoxicity in 16 (32%) and grade 2-3 asthenia in 25 (51%). Other toxicities were mild. CONCLUSIONS The paclitaxel-gemcitabine combination is a well-tolerated and relatively active salvage regimen in patients with NSCLC and it merits further investigation.

Endometrial Cancer: What Is New in Adjuvant and Molecularly Targeted Therapy?

Endometrial cancer is the most common gynaecological cancer in western countries. Radiotherapy remains the mainstay of postoperative management, but accumulating data show that adjuvant chemotherapy may display promising results after staging surgery. The prognosis of patients with metastatic disease remains disappointing with only one-year survival. Progestins represent an effective option, especially for those patients with low-grade estrogen and/or progesterone receptor positive disease. Chemotherapy using the combination of paclitaxel, doxorubicin, and cisplatin is beneficial for patients with advanced or metastatic disease after staging surgery and potentially for patients with early-stage disease and high-risk factors. Toxicity is a point in question; however, the combination of paclitaxel with carboplatin may diminish these concerns. In women with multiple medical comorbidities, single-agent chemotherapy may be better tolerated with acceptable results. Our increased knowledge of the molecular aspects of endometrial cancer biology has paved the way for clinical research to develop novel targeted antineoplastic agents (everolimus, temsirolimus, gefitinib, erlotinib, cetuximab, trastuzumab, bevacizumab, sorafenib) as more effective and less toxic options. Continued investigation into the molecular pathways of endometrial cancer development and progression will increase our knowledge of this disease leading to the discovery of novel, superior agents.

Prophylactic antibiotics for the prevention of neutropenic fever in patients undergoing autologous stem-cell transplantation: results of a single institution, randomized phase 2 trial.

One hundred and fifty‐seven patients undergoing high‐dose chemotherapy (HDT) and autologous stem‐cell transplantation (ASCT) for hematopoietic malignancies and solid tumors were randomly assigned to receive (Group A) or not (Group B) prophylaxis with ciprofloxacin, orally, and vancomycin, intravenously. Prophylactic antibiotics were given from day 0 until resolution of neutropenia or the appearance of a febrile event. Furthermore, patients in both groups received once a day fluconazole, orally. The primary end‐point of our study was the incidence of neutropenic febrile episodes attributed to infection. One hundred and twelve (71.3%) patients developed neutropenic fever, 50 (56.2%) in Group A and 62 (91.2%) in Group B (P < 0.001) with the majority (82%) of patients developing fever of unknown origin. Patients on prophylactic antibiotics had a significantly lower rate of bacteremias (5.6%) than did those randomized to no prophylaxis (29.4%) (P = 0.005) and, when developing neutropenic fever, they had a lower probability of response to first‐line empirical antibiotics (P = 0.025). Prophylactic administration of ciprofloxacin and vancomycin reduced the incidence of neutropenic fever in patients receiving HDT with ASCT, however, without affecting the total interval of hospitalization, time to engraftment, or all‐cause mortality. Therefore, our results do not support the use of antibiotic prophylaxis for patients undergoing HDT and ASCT. Am. J. Hematol., 2010.